Her is one cleaver little fellow which lucky for us is now exterminated to only a few areas.
It is transmitted via fly bites and the larva are cleaver they disburse in the blood stream during the daytime and hope a fly bites you so it can be transmitted on down the road. At night they swarm your lungs nice am warm I guess.
The adult worm will travel you body causing itching feeling here and there but are easily visible if they reach you eye. you will feel it moving around in there and it can be easily removed by a qualified doctor.
The worm in and of itself is quite harmless but if heavily infested the removal can cause you harm.